CDF physicists have previously measured the rate of the matter-antimatter transitions for the B_s meson, which consists of the heavy bottom quark bound by the strong nuclear interaction to a strange antiquark.

The subsample in question came to light in the course of the measurement of the b quark pair production cross section, which is proportional to the rate at which events with a b quark and a b antiquark are produced.

Quanta devoid of internal structure (such as quarks, leptons, and intermediate bosons) are the result of interaction with one quantum of space; particles endowed with internal structure (baryons constituted of three quarks and mesons made up of a quark-antiquark pair) are the product of interaction with several QS.